Which fighters were "thick skinned?"

[DAVIDICUS]

RG_Lunatic,

When did production Corsairs finally do away with fabric covered control surfaces?

[FLYBOYJ]

Originally Posted by RG_Lunatic

FlyBoyJ,

Somewhere on the Dupont website is (or there was) a section concerning the fabric covering for the wings of the Corsair, which was a synthetic fabric which would not rip or tear (a for-runner of Tyvex). It was soaked in another Dupont chemical which it turned out was very harsh on the skin and lungs of the flight crews, in order to make it virtually fireproof. It had to be replaced frequently because it did have a tendancy to stretch.

This fabric was used on the wings to make them less susceptable to damage. I don't know if it was used on the other surfaces or not.

As I said before, the wings of all flying corsairs today use duraluminum, not fabric of any kind - so obviously the FAA is not quite so strict as you claim. Modifications can get approval.

=S=

Lunatic

That's what you think RG - the Feds are VERY strict. As Evan stated earlier, if you start changing wing skin sizes the airplane will fly VERY different, something a little hair raising when you're flying a 60 year old restored war bird! Yes, you can do engineering changes, but it can be very difficult, and even though a DER can come up with very rational engineering, an airworthy inspector can shoot it down for any reason he or she seem fit. Their power is immense! I've seen Corsairs with their center wing fabric section replaced with sheet metal, I believe some of that might of been done when the aircraft were still operational, probably after the war. Something like that isn't a great deal, its when you start messing with control surfaces when things could get sticky.

The synthetic fabric you are talking about is probably ceconite, and the chemicals used were harsh, but that was and still is common in dealing with rag wing aircraft. The people who came up with Stits process did so to get rid of the dopes and acetones needed during the "old" process and yes, many of the dopes used on ceconite and Irish Linen are fireproof. The fabric and dope process is the same, whether you're covering the center section of a restored F4U or a piper cub, I state this through experience. I helped rebuild a number of war birds and/ or their sub assemblies (P-51, F4U, MiG-15, PBY, S-2, F-86, C-123, L-29, and numerous older UH-1H to name a few) and did the licensing process with the FAA on probably 20 or 30 of them. As a matter of fact, I do high performance aircraft FAA certification consulting as a side business (do you know anyone with a P-51 that needs to be licensed?)

I could tell you (and I think Evan can back me up on this) when you restore a war bird, you want to make it as original as possible. Things like nav lights, landing lights and certain nav equipment may have to be added per the FAA. The owner may go through the cockpit and make it more "use friendly" By modifying the seat, adding modern radios and GPS.

I worked with a guy who had a saying "Unless its going to kill, get you thrown in jail or you or give you hemriods, keep it original."

[FLYBOYJ]

Originally Posted by DAVIDICUS

RG_Lunatic,

When did production Corsairs finally do away with fabric covered control surfaces?

I think the later F4Us eventually went to metal control surfaces after WW2. I know that after WWII there was a great push to do away with fabric control surfaces in the military due to the hazardness of the materials and the specialty skill required to do fabric work. On an aircraft carrier its bad enough you have bilges filled with fuel and bombs on board, if you could avoid one less flammable item, the better! Dope and fabric work today is just about a lost art. Personally I hate to do it because of the time process, the smell and the hassle to correct a mistake. It's much easier to bang away on sheet metal!

[evangilder]

There are a few people still around that can do the fabric. I have a couple of cousins that are very good at it. Their father taught them (he had an aircraft maintenance hangar in Yuma Arizona for years, Burch Aviation) and as far as I know, they still can do it well. Sadly, it is becoming a lost art.

[evangilder]

And yes, at least in the CAF, they try and make it as original as possible. I recently found out that the B-25 we are restoring is actually the only surviving PBJ. There are other PBJ-like airplanes that are really B-25s painted and modified to look like a PBJ, but our started it's life as a PBJ and it looks like it will be restored as such. They are using original blueprints to fabricate some of the metal structure that has corroded and/or been removed. The aircraft had the bomb-bay removed in it's previous existence as a post-war transport. They have rebuilt the bomb-bay from parts fabricated in-house using original drawings and the same guage of metals.

[FLYBOYJ]

Originally Posted by evangilder

They have rebuilt the bomb-bay from parts fabricated in-house using original drawings and the same guage of metals.

And those drawings are considered "approved data" by the FAA.

[plan_D]

Random fact of the day, my Great-Grandfather was a rigger in World War 1. He did the fabric covering and rigging of the aircraft.

[FLYBOYJ]

Originally Posted by plan_D

Random fact of the day, my Great-Grandfather was a rigger in World War 1. He did the fabric covering and rigging of the aircraft.

Do you know what aircraft he worked on?

Originally Posted by evangilder

Okay, I misunderstood. I wasn't aware that late model Corsairs had any fabric in the wings, aside from the elevators and the rudder. I always consider the elevators part of the wing.

The F4U-5 was the first Corsair that had fully metal wings, and I believe all tail surfaces were metal as well. I'm not sure about the ailerons.

The F4U-4 had a special fabric covering for the wings aft of the spar outside of the fold, and the ailerons were made of wood. Control surfaces on the tail were fabric covered, but I don't know if it was the same fabric or normal canvas - the comment about the fabric from Dupont only referred to the wings.

As far as I know, all flying (and perhaps static) F4U's, even the -1's, have been redone in aluminum - the fabric is just impossible to get and a royal pain to service.

=S=

Lunatic

Originally Posted by FLYBOYJ

That's what you think RG - the Feds are VERY strict. As Evan stated earlier, if you start changing wing skin sizes the airplane will fly VERY different, something a little hair raising when you're flying a 60 year old restored war bird! Yes, you can do engineering changes, but it can be very difficult, and even though a DER can come up with very rational engineering, an airworthy inspector can shoot it down for any reason he or she seem fit. Their power is immense! I've seen Corsairs with their center wing fabric section replaced with sheet metal, I believe some of that might of been done when the aircraft were still operational, probably after the war. Something like that isn't a great deal, its when you start messing with control surfaces when things could get sticky.

The synthetic fabric you are talking about is probably ceconite, and the chemicals used were harsh, but that was and still is common in dealing with rag wing aircraft. The people who came up with Stits process did so to get rid of the dopes and acetones needed during the "old" process and yes, many of the dopes used on ceconite and Irish Linen are fireproof. The fabric and dope process is the same, whether you're covering the center section of a restored F4U or a piper cub, I state this through experience. I helped rebuild a number of war birds and/ or their sub assemblies (P-51, F4U, MiG-15, PBY, S-2, F-86, C-123, L-29, and numerous older UH-1H to name a few) and did the licensing process with the FAA on probably 20 or 30 of them. As a matter of fact, I do high performance aircraft FAA certification consulting as a side business (do you know anyone with a P-51 that needs to be licensed?)

I could tell you (and I think Evan can back me up on this) when you restore a war bird, you want to make it as original as possible. Things like nav lights, landing lights and certain nav equipment may have to be added per the FAA. The owner may go through the cockpit and make it more "use friendly" By modifying the seat, adding modern radios and GPS.

I worked with a guy who had a saying "Unless its going to kill, get you thrown in jail or you or give you hemriods, keep it original."

I think I've seen every US based flying Corsair. I always check the wings, so far I've never seen one with fabric covering.

You keep saying "center section", the part of the wing that was covered in fabric was that aft of the spar outside the fold (bend). The ailerons were wood (metal was also tested but wood was found superior).

I would imagine that since the F4U-5 and beyond had "all metal" wings (ailerons???) and there was no other significant change to the wing design that the conversion of F4U-1's through F4U-4's to metal would be somewhat simplified. Factory specs for all metal wings already exist.

Service F4U-4's had fabric wings through at least Korea, I'm not aware of the USN ever refitting them.

=S=

Lunatic

[FLYBOYJ]

Originally Posted by RG_Lunatic

I think I've seen every US based flying Corsair. I always check the wings, so far I've never seen one with fabric covering.

You keep saying "center section", the part of the wing that was covered in fabric was that aft of the spar outside the fold (bend). The ailerons were wood (metal was also tested but wood was found superior).

I would imagine that since the F4U-5 and beyond had "all metal" wings (ailerons???) and there was no other significant change to the wing design that the conversion of F4U-1's through F4U-4's to metal would be somewhat simplified. Factory specs for all metal wings already exist.

Service F4U-4's had fabric wings through at least Korea, I'm not aware of the USN ever refitting them.

=S=

Lunatic

The Museum in Chino Ca. had several older F4Us with fabric wing center sections. I seen them back in 1978 when I had to do an A&P apprenticeship project. There were 2 or 3 from what I remember, but they were not restored and were missing the outboard wing sections. The fabric was all rotted through. What happened to them, I'll never know.

You're probably right on the -5s being all metal, but are you sure of the control surfaces being wood? I believe they were an aluminum frame covered with fabric. Repairing wood is even more difficult than fabric and even when varnished, wood shrinks. I think the changing climate and salt air on a carrier would play havoc on a wood control surface.

[FLYBOYJ]

The control surfaces on the F4U I seen during the Gillespie airshow were definitely fabric, I took a photo and you could see the stitching and finishing tape in the rudder and elevators (C&P and zoom in on it). The sun his hitting the aileron, but I think it too was fabric covered. I'm keeping this photo a lot smaller than the previous ones

[FLYBOYJ]

You know RG - I stand corrected, the ailerons were wood! I found a picture of one undergoing restoration. See attached!

Go to this site, they got some nice F4U and other warbird restoration photos - I dealt with these guys a few times, nice people!

http://www.americanaeroservices.com/f4u-5_home.htm

[plan_D]

Sorry, Flyboy, I don't know. I have a picture of him stood next to a plane but I don't have a scanner. And the picture is in bad condition.

[KraziKanuK]

factory F4U drawings, http://www.f4ucorsair.com/tdata/blueprints.html